Speed problem HPM5000B

[Blongo]

Hi there

some time ago I bought a goldenmotor HPM5000B 48V. Since the datasheet shows ~4000 rpm without load
at 48V, I'm a bit confused since I get ~2000 rpm at 48V w/o any load (100 % PWM duty cycle).
So I would like to know if there are different versions of the motor ?
Any help is appreciated!

Thanks in advance,
Chris

[Bikemad]

Hi Chris andto the forum.

According to the GM Website there are six versions of the HPM5000B motor:

48V Air Cooled
72V Air Cooled
96V Air Cooled
48V Liquid Cooled
72V Liquid Cooled
96V Liquid Cooled

I would expect ~2000rpm from a 96V motor running on 48V.

Take a look at this post for more info on the motor voltages.

Alan
 

[Henry Chang]

I would expect ~2000rpm from a 96V motor running on 48V.


Then measure  resistance value

[Blongo]

Hi guys and cheers for the warm welcome !

I measured the resistance from one phase to another to be 17 mOhm.
Since the website says that the 48V version should have 6.2 mOhm, I'm
almost sure, that it is not the 48 V model. There's no information about the
phase resistance of the 96V verision. Is it plausible to be the 96V version with
17 mOhm?

Thanks for the hints!
Chris

[Henry Chang]

Today measure 96V stator winding, it is about 31 milliohm.

[Bikemad]

Phase Resistance (Milliohm): 6.2/48V; 12.0/72V; 36.0/120V

Today measure 96V stator winding, it is about 31 milliohm.

Henry, is there a 120V motor in addition to the 96V motor advertised on the website?

The motor's KV (rpm/volt) appears to be ~84 for both the 48V and 72V performance figures, which makes me think that the same 48V motor may have been used for both of these tests.

The motor used for the 104V performance figures (presumably the 96V motor?) has a KV of ~49, which would indicate that the windings are definitely different on this particular motor.

Chris, which controller were you using with your motor and how did you actually measure your rpm?

If you used an optical tachometer designed for measuring propeller speed like this one:

You would have needed two markers 180 degrees apart on the shaft to give the correct rpm reading.

If a single marker (or perhaps the keyway slot?) was used (with the tachometer on the 2 blade setting) the displayed rpm reading would have been half of the actual shaft rpm, which might explain why you only measured ~2000rpm instead of the expected ~4000rpm at 48V.

Alan
 

[Blongo]

Hi guys,

I use a non-GM controller which simply commutates the field based on the hall-signals. The speed
is analysed based on the hall signals. The speed evaluation works, at low speeds the manually counted
speed fits to the analysed one.

My motor has a KV of ~49. I get ~1750 rpm at 36V and ~2300 at 48V. So my question is. Is there a
motor where the KV of 49 and the phase resistance of ~17 mOhm fits to?

Is it correct that the phase resistance is measured from one phase to another one right?

Thanks in advance and best regards,
Chris

[Morgen 3Eman]

Just to further muddy the waters,  if we measured phase to phase with the 31mOhm windings in a delta  connected stator, the reading would be about 20 mOhms.  So how did each of you actually make your measurements? 

TTFN,
Dennis

[Blongo]

So I think we have to clear two things.

How is "phase resistance" defined? Is it the resistance from one phase to another or
is it the reistance of one phase?

What is the winding type of the HPM5000B? Is it star or delta?

I measured the 17 mOhm from one phase to another...

Cheers,
Chris

[Henry Chang]

Mayber controller also has the highest speed limit ...


Star.

[Blongo]

Hi Henry,
thanks for you reply. The controller has no speed-limit, it was programmed by myself :-). How did you measure the phase resistance?
From one phase to another? And do you know how the phase resistance on gm-website is meant?

Cheers,
Chris

[Henry Chang]

Bring my photos(photograph twice, take a picture in computer), I measure the stator winding,  and if you measure the whole motor, the milliohms are different (even your motor are 96v5kw), so I make a mistake, there are some factors impact on phase resistance while measure a whole motor, and phase resistance of GM website should is stator winding's.

Later, I measure 120 v phase resistance to be about 39 (Milliohm), not 36 (Milliohm), the parameters of the website for a long time not updated.